Focus Cooling

[ronlock]

In my experience, a realtively small cowl opening
directed at the cylinder and head area is sufficient.
I do add some baffeling to try and keep the intake
air directed around the cylinder and head.
My last four pattern birds (including a Focus not yet
flown) have openings about 1 1/4 inch wide and 2 inches
high. For exit air, I follow the general rule that exit
openings should be at least twice the size as entry.
This has worked fine on a YS 1.20, OS 1.40, and
ST 1.40.   (including Muncie heat at NATS)

I do not open the cheek areas- I don't thinks it
is good to let air into a cowl that doesn't directly
cool the engine.  It just competes with cooling
air for exit area.   I know there is a current
interest in cooling air for rear bearings.   For
2 and 4 strokes that flood the crankcase with
fuel/air mixture, I can't (yet?) make myself
believe the rear bearing needs air cooling.

Later, Ron Lockhart

----- Original Message -----
From: "Bill Glaze" <billglaze at triad.rr.com>
To: <discussion at nsrca.org>
Sent: Thursday, November 14, 2002 10:51 AM
Subject: Re: Focus Cooling


> Chuck:
> Stock cutouts working fine for me, but I'm running Y.S. 1.40 FZ.  Seems
plenty
> cool.  In fact, If I had it to do over, I'd give thought to not even
cutting out
> the upper cheek cutouts.  Air circulation from around the large cutout
that
> services the head area seems to be O.K.  At first I didn't cut out the
cheek
> portion, and was having engine problems I thought were related to cooling.
So,
> I cut them out, only to find out that the problem was elsewhere.  If I get
> another cowl for any reason, I'll not cut out the upper portions.  Of
course,
> I'm not sure if the 1.60 could survive under those circumstances.
>
> Bill Glaze
>
> Chuck Czarnik wrote:
>
> > Been reading the discussions of bearing life and cooling / fuel choice,
etc.
> > with great interest.  I have my first Focus almost ready to go, but now
I'm
> > curious if the scribed holes on the cowl will get enough air to the
engine.
> > This OS 1.60 is over twice the size of anything I've ever owned, so I'm
in
> > new territory here.  Cowl has the std. cutouts on each cheek, in front
of
> > the cylinder, and a TT LBP spinner.  Other Focii owners, should I open
it up
> > any more? Thanks in advance, Chuck
> > =====================================
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